180021001 has 2 divisors, whose sum is σ = 180021002. Its totient is φ = 180021000.

The previous prime is 180020989. The next prime is 180021053. The reversal of 180021001 is 100120081.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 150307600 + 29713401 = 12260^2 + 5451^2 .

It is a cyclic number.

It is not a de Polignac number, because 180021001 - 2⁵ = 180020969 is a prime.

It is not a weakly prime, because it can be changed into another prime (180021071) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90010500 + 90010501.

It is an arithmetic number, because the mean of its divisors is an integer number (90010501).

Almost surely, 2^180021001 is an apocalyptic number.

It is an amenable number.

180021001 is a deficient number, since it is larger than the sum of its proper divisors (1).

180021001 is an equidigital number, since it uses as much as digits as its factorization.

180021001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 180021001 is about 13417.1905032313. The cubic root of 180021001 is about 564.6435750276.

Adding to 180021001 its reverse (100120081), we get a palindrome (280141082).

It can be divided in two parts, 1800 and 21001, that added together give a square (22801 = 151²).

The spelling of 180021001 in words is "one hundred eighty million, twenty-one thousand, one".